JPH022322B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a microwave amplification device, and in particular to a microwave amplification device that uses a plurality of microwave semiconductor amplifier modules (using FETs made of gallium or arsenic compounds, etc.) connected in series. This invention relates to a structure that reduces the amount of attenuation of the signal power of a housed microwave amplifier by an electromagnetic wave absorber provided in a metal container.

Recently, a simple microwave amplification device has been developed that uses a semiconductor device as an amplifier module in a package and connects multiple packages to multiply the gain of a single package, and has been widely used. has been done.

However, such a microwave amplifier is
Because the metal casing acts like a kind of waveguide for the transmitted microwave signal, the metal casing has frequency characteristics that allow the signal to spread uniformly over a wide frequency band without attenuation. There are many problems in transmission.

For example, if a metal casing has a resonant frequency at a specific frequency in the transmission frequency band, the frequency characteristics of a microwave amplifier will become non-uniform, and the output terminals of multiple amplifier modules arranged in a metal casing will There is a disadvantage that oscillation occurs when the microwave output from the side is fed back to the input side.

As a countermeasure to this problem, a microwave absorber is usually installed inside the metal lid of the metal casing to absorb electromagnetic waves that make the operation of the microwave amplifier unstable. Therefore, there is a drawback that the microwave power is attenuated, and improvement of this problem is desired.

[Conventional technology]

FIG. 2 is a perspective view of the microwave module. Microwave module 1 has a small external shape and a hermetic structure, and has a frequency band of 8 GHz to 8 GHz.
It is designed to have a gain of 5 dB or more over 18 GHz, and DC and RF terminals 3 are provided on the side of the package 2 so that multiple microwave modules can be easily cascaded. ing.

Figure 3a is a plan view of the microwave module;
3b is a front view thereof, and FIG. 3c is a side view thereof, and the reference numerals are the same as in FIG. 2.

FIGS. 4a to 4c show a microwave amplification device for explaining a state in which microwave modules are connected in series and arranged inside a metal casing.

In Fig. 4a, a plurality of microwave modules 1 are connected in series and housed inside a metal casing 11. If the gain of one module is 5 dB, four modules are connected in series. Then, about
Gain of 20dB can be obtained.

An input terminal 12 and an output terminal 13 are provided at both ends of the metal housing 11, and these terminals are connected to microwave modules located at both ends, and each microwave module is connected to the microwave module. They are connected through a terminal section 14.

FIG. 4b shows a cross-sectional view of the metal lid of the microwave module, and FIG. 4c shows a plan view of the metal lid of the microwave module.

Since the housing to which the metal lid 15 is attached becomes a kind of waveguide, the frequency characteristics of the microwave amplifier, oscillation due to feedback of electromagnetic waves between the input and output terminals, and the frequency characteristics of the gain deteriorate. Therefore, the casing is designed to be as compact as possible, with no resonant frequency in the frequency band.

Conventionally, in order to prevent the return of such electromagnetic waves, an electromagnetic wave absorber 16 such as ferrite rubber is attached to the inside of the metal lid 15.
It absorbs leaked electromagnetic waves, allowing relatively stable operation.

However, due to the small size of the casing, the electromagnetic wave absorber 16 is placed quite close to the connection part 14 of the microwave module, and this electromagnetic wave absorber absorbs not only the leakage electromagnetic waves of the microwave but also the electromagnetic wave absorber 16. , the signal power at the interstage portion where each microwave module is connected is absorbed by a nearby electromagnetic wave absorber, resulting in a disadvantage that the microwave transmission efficiency is attenuated.

[Problem that the invention seeks to solve]

The problem is that part of the energy of the high-frequency signal is absorbed by the electromagnetic wave absorber installed in the metal lid to absorb the waveguide mode, which reduces the gain of the high-frequency amplifier. This causes a problem.

[Means for solving problems]

The present invention provides a microwave amplification circuit that solves the above problems, and includes a plurality of cascaded semiconductor amplifier modules housed in a metal container having an input terminal and an output terminal. In a microwave amplification device, the metal container is sealed with a metal lid having an electromagnetic wave absorber coated on the top surface, and the electromagnetic wave absorber is attached to the electromagnetic wave absorber corresponding to the interstage portion to which the plurality of semiconductor amplifier modules are connected. This can be achieved by a microwave amplification device that is provided with an opening to reduce attenuation of the signal transmitted by the semiconductor amplifier module.

[Effect]

In the present invention, when a plurality of microwave modules are connected and housed in a housing, the conductor is exposed at the connecting portion of each microwave module, so that the electromagnetic wave absorber approaches this. In order to prevent the signal power from being absorbed and the gain to decrease, the part of the electromagnetic wave absorber that is closest to the connection part of each microwave module is installed so as not to absorb electromagnetic waves.
By providing the opening, consideration was given to preventing electromagnetic waves from being absorbed.

〔Example〕

FIG. 1a and FIG. 1b show schematic plan views of a housing portion and a metal lid of a microwave amplification device for explaining an embodiment of the present invention.

In FIG. 1a, a plurality of microwave packages 1 are connected in series, and the connecting terminals 3 of the respective microwave modules are exposed at the connecting portions 14 thereof.

The more the frequency of the input/output signal becomes a microwave, the more microwave electromagnetic waves will be radiated from this exposed connection terminal 3. If there is a resistor in the vicinity, the radiation loss will normally be reduced by the amount of radiation loss at the next stage. The input to the wave package is reduced.

In order to reduce radiation loss from the exposed connection conductor as much as possible, the present invention provides a microwave absorber 16 attached to the metal lid 15 opposite to the exposed connection terminal portion 14. , an opening 17 is provided, and as a result, the loss in the microwave amplification device was conventionally about 1 dB, but as a result of providing the opening in the microwave absorber of the present invention, the loss is about 0.1 dB. It was improved to the point of loss, and a remarkable effect was recognized.

〔Effect of the invention〕

As explained in detail above, the microwave amplification device of the present invention has a great effect in that it can provide a microwave amplification device that has excellent characteristics with high gain and little gain fluctuation with respect to broadband frequency characteristics. There is something.

[Brief explanation of drawings]

1a and 1b, FIG. 1c is a front view and a sectional view of the microwave amplification device of the present invention, and FIG. 2 is a
Figures 3a, 3b and 3c are perspective views of the microwave module, respectively. Figure 4c is a cross-sectional view and a plan view of a conventional microwave amplification device. In the figure, 1 is a microwave package, 3 is a connection terminal, 1
4 is a connection part of the microwave package, 15 is a metal lid, 16 is a microwave absorber, 17 is an opening,
are shown respectively.

Claims (1)

[Claims] 1 A plurality of semiconductor amplifier modules connected in series are housed in a metal container having an input terminal and an output terminal, and the metal container is sealed with a metal lid whose top surface is coated with an electromagnetic wave absorber. A microwave amplification device, characterized in that an opening is provided in the electromagnetic wave absorber corresponding to an interstage portion to which the plurality of semiconductor amplifier modules are connected.